Efficacious SARS-CoV-2 vaccines are urgently required to prevent the spread of the emerging and re-emerging SARS-CoV-2. Aim to assess the efficacy of novel SRAS-CoV-2 vaccines in preventing SARS-CoV-2 infection. All randomized placebo-controlled clinical trials eligible for this review were included. Scopus, PubMed, the Cochrane Library, and Google Scholar were searched. The risk of bias in the included studies was assessed using the modified Cochrane risk of bias tool 2 for RCTs. Result synthesis was performed using STATA software version 17.4. Forest plots, heterogeneity tests, meta-regression, sensitivity analysis, and publication bias were used to present the results. Eighteen studies comprising 186,657 participants who took the full dose of SARS-CoV-2 in an RCT were included. Of the participants, 110,768 (59.3%) were males and 111,619 (59.8%) were treatment groups. A total of 5665 (3.0%) participants were infected by SARS-CoV-2. Among the treatment groups, 3140 (2.8%) and 2525 (3.4%) from the placebo group were infected by SARS-CoV-2. The most efficient SARS-CoV-2 vaccine was BNT162B2, with 100% efficacy, whereas mRNA-1273 was the least efficient vaccine, with 36.8% efficacy. The overall efficacy of novel SRAS-CoV-2 vaccines was 70.5% (95% confidence interval (CI), 53.5 to 79.7). The relative risk of being infected was 84% lower in the treatment group compared to the placebo group. The novel SRAS-CoV-2 vaccines are efficient enough to protect 771 people out of 1000 from being infected by SARS-CoV-2. Novel SARS-CoV-2 vaccines are efficacious inn preventing SARS-CoV-2 infection. However, their efficacy varies.

Fires in the Amazon Rainforest have surged to record-breaking levels, highlighting the region’s ‘growing ecological fragility'.